Vital Sign Monitoring: Status & Trends of Established Invasive Plants

Documenting the locations of the attractive but invasive Kahili ginger (Hedychium gardnerianum) is a major task in Hawaii Volcanoes National Park

Description & Rational
Nonnative plant species invasions present a serious threat to Pacific island ecosystems. Invasion by nonnative plants reduces native plant diversity and abundance, and alters vegetation structure. Ecologically disruptive species (e.g., nonnative grasses, Morella faya, Miconia calvascens, Psidium cattleianum) displace native vegetation and alter ecosystem processes. Nonnative plant invasions can also lead to significant economic and cultural costs. For example, nonnative grasses are responsible for increased fire frequency and spread in wildland urban interfaces, and the loss or alteration of culturally significant species and landscapes. Monitoring of the distribution and abundance of nonnative species is required to assess the changing threats to native ecosystems, formulate appropriate control strategies (e.g., eradication, containment, exclusion, monitoring), and prioritize areas for management.

Brief Monitoring Questions & Objectives
Question 1: Within selected focal plant communities and natural areas of concern across PACN parks, what are the changes in the distribution and abundance of disruptive nonnative plant species?

Monitoring Objective 1: Determine the changes in the distribution and abundance of disruptive nonnative plant species along belt transects spanning select focal plant communities and natural areas of concern in PACN parks.  Belt transects will consist of a mixture of legacy transects and newly generated random transects. 

Question 2: In the major dispersal corridors (e.g., roads, fencelines, building areas, etc.) of PACN parks, what are the changes in the distribution and abundance of disruptive nonnative plant species? 

Monitoring Objective 2: Determine the changes in the distribution and abundance of disruptive nonnative plant species within and around major dispersal corridors in PACN parks.  Major dispersal corridors consist of areas where human factors (e.g., seeds on vehicles, boots, field equipment, etc.) are the primary vector for spreading invasive plant species.  This objective aims to monitor established invasive plant species as well as incipient invaders.    

Vital Sign Monitoring Status & Trends
The Status and Trends of Established Invasive Plant Species monitoring protocol is in development and is scheduled to enter into peer review in late 2009.

Products and Related Links:

• Protocol Documents (in development)

Education and Outreach

• Status and Trends of Established Invasive Plants Monitoring Movie – Coming Soon!
• Status and Trends of Established Invasive Plants Monitoring Photo Gallery - Coming Soon!

Scarlet gourd (Coccinia grandis) is one of many invasive plants that threaten native ecosystems in PACN parks

Contact Information
I&M Lead:
Alison Ainsworth
Botanist, Pacific Islands Network I&M
Hawaii Volcanoes National Park, HI 96718
alison_ainsworth <at> nps.gov

Principal Investigators:
Dr. Jim Jacobi
US Geological Survey
Hawaii Volcanoes National Park, HI 96718
jim_jacobi <at> usgs.gov

Dr. Rhonda Loh
National Park Service
Hawaii Volcanoes National Park, HI 96718
rhonda_loh <at> nps.gov